/Engine/Source/Editor/BlueprintGraph/Public/BlueprintActionDatabaseRegistrar.h
Each action should be recorded under a specificUFieldkey; primarily to refresh those actions when the corresponding asset is updated (Blueprint regenerated, struct added/deleted, etc.).
bool AddBlueprintAction ( [UClass](API\Runtime\CoreUObject\UObject\UClass) const * ClassOwner, [UBlueprintNodeSpawner](API\Editor\BlueprintGraph\UBlueprintNodeSpawner) * NodeSpawner )